According to Intel's Website, my Q9550 processor should support Hardware Virtualization. (It says on the box and many other sources too, so the website isn't wrong). However, according to Microsoft's tool and VirtualBox, this is not the case. I also have a Gigabyte P35-DS3L with Award Software International, Inc. F5, 9/7/2007 BIOS. There is no setting in my bios to enable hardware virtualization. I am thinking that I need to update my BIOS, but don't want to unless necessary. Is this the case? I am running Win7 x64 on host system.

I'm also using VirtualBox with me. But I use J&W G41HD2 motherboard with 8GB DDR3 RAM. Basically, our Q9950 has the VT-X and VT-D feature for virtualization.

If I'm not mistaken P35 is using DDR2 right? Try to change it into G41 with DDR3 RAM. Use at least 8GB DDR3 RAM for virtualization in Win 7 64bit.

In VirtualBox, those features will be activated automatically. If you want to find out how fast is visualization runs on your computer without VT-X and VT-D, try install VMPlayer and disable the virtualization hardware support. You can see how ugly the performance without VT-X and VT-D in Q9550.

Then you try to activated the virtualization on VMPLAYER with virtualization hardware support.

If the performance in VMPLAYER with virtualization support almost a same within Oracle Virtual Box, then you are already at its top.

My suggestions are : Try to use 8GB DDR3 RAM. I ever experienced running virtualization with 4GB DDR2 RAM in Win 7 64bit. This is slow.... XP runs much faster in this case.